The present invention relates to a pulley system for use in a belt driven mower assembly having an endless drive belt. More particularly, this invention relates to a clutching sheave that automatically releases the driving belt from driving engagement with the pulley system when the mower assembly is raised to a non-use position and automatically re-engages the belt when the mower assembly is lowered to the use position.
Belt driven mower units having a suspended mower assembly that can be raised and lowered to use and non-use positions are common. Typically, the assembly is hydraulically attached to the unit through parallel links and can be raised and lowered from the tractor seat. However, the operator must remember to disengage the mower blade when the mower assembly is raised because, in general, there is no way to automatically stop the mower blades from spinning. Also, starting the motor with the pulley assembly and blades engaged is more difficult due to the starter being operatively connected to the pulley system and having to turn not only the motor but the entire pulley system. This makes starting of the motor difficult, if not impossible, and reduces battery, starter, and belt life.
The present invention overcomes the above disadvantages by providing a clutch mechanism that is simply constructed and automatically disengages the belt from the pulley system as the mower assembly is raised. There is also provided a braking means that prevents the belt from turning in the raised position, a belt guard that prevents the belt from entirely separating from the pulley system and an in interlock system that only permits the motor to be started in the raised position with the belt disengaged. Further, a belt tension adjusting means is provided to insure proper belt tension.